The present invention broadly relates to dosing and mixing apparatus and, more specifically, pertains to a new and improved construction of a dosing and mixing apparatus for fluid media
Generally speaking, the dosing and mixing apparatus of the present invention comprises at least one delivery element and at least one isolating element. These elements respectively comprise through-flow openings or transfer passages and dosing openings or dosing chambers suitably constructed and suitably mutually arranged for accommodating and isolating at least one voluminized specimen quantity or at least one measured dose of test specimen as well as for delivering this dose of test specimen to and mixing this dose of test specimen with a voluminized thinning agent i.e. a measured dose of diluent or thinning agent.
A dosing and distributing apparatus is known from the German Patent publication No. 1,773,226, which essentially comprises two outer components and an intermediate component arranged therebetween and journaled to pivot about a shaft. Transfer openings or passages are provided in the individual plate-like components in suitable mutual arrangement and can be either brought into communication with one another or interrupted by a suitable pivoting motion of the intermediate component. This apparatus serves for accommodating and isolating a predetermined specimen quantity and for mixing this specimen quantity with a predetermined quantity of thinning agent.
A further dosing and distributing apparatus is known from the German Pat. No. 2,854,303, which is composed essentially of a rotatable intermediate component as well as a first and second stationary external component. The intermediate component and both external components are constructed as discs and are arranged coaxially upon a spindle. The external components are in contact with the intermediate component by means of surfaces facing toward the intermediate component. These individual components are provided with suitably constructed and arranged transfer apertures for accommodating, isolating and delivering a fluid specimen quantity with a quantity of thinning agent.
In the known dosing and distributing apparatuses, the fluid specimen to be analyzed, for instance a blood specimen, is transported from a first position into a second position for charging it with a predetermined quantity of thinning agent. Viscous-film specimen deposits arise in this procedure, especially in the transfer region between the surfaces of the individual components or elements in mutual contact, which cause an adhesive effect which interferes with operation and therefore requires costly maintenance and cleansing work at relatively short time intervals.